在程序集8086中编写一个过程，该过程将从C接收以下信息：
int *matrix[size], int size, int *num1, int *num2.
我首先将其写为小型模型，但效果很好，当我将其转换为大型模型时，它停止了正常工作，我尝试更改循环计数，将“行指针”加4，将“列指针”加2（都尝试加4，反之）。
该过程应检查最小值（绝对值），即最小值| x-y |。 例如，该过程将获得N个数字，并将其从所有其他数字中减去，并始终保存| x-y |的最小值。然后，它将N个数字向前移动一个数字，并与其余数字相同，直到所有矩阵都被选中为止。
C代码（此代码不能更改任何内容）：
#include <stdio.h>
#include <stdlib.h>
extern int getDiffMin(int *mat[], int size , int *num1 , int *num2);
int main()
{
int
diff , i, j , num1 , num2;
int **mat = (int **)malloc(sizeof(int *) * 4);
for (i = 0; i < 4; i++)
mat[i] = (int *)malloc(sizeof(int) * 4);
for (i = 0; i < 4; i++)
for (j = 0; j < 4; j++)
mat[i][j] = (i*j) - (5 * i) - (14 * j);
for (i = 0; i < 4; i++)
{
for (j = 0; j < 4; j++)
printf("%d\t", mat[i][j]);
printf("\n");
}
diff = getDiffMin(mat, 4 , &num1 , &num2);
printf("\nminDiff == |(%d)-(%d)| = %d", num1 , num2 , diff);
for (i = 0; i < 4; i++)
free(mat[i]);
free(mat);
return 0;
}
组装代码：
;extern int getDiffMin(int *mat[], int size , int *num1 , int *num2)
; BP+6+8 BP+10 BP+12+14 BP+16+18
;
.MODEL LARGE ;Pointers size = 4 bytes
.DATA
I DW ?
J DW ?
N DW ?
Min DW ?
TempI DW ?
TempJ DW ?
Counter DW ?
Two DW 2
.CODE
.386
PUBLIC _getDiffMin
_getDiffMin PROC FAR
Start:
PUSH BP ;Save BP's current value
MOV BP,SP
PUSH SI
PUSH DI
PUSH CX
PUSH ES
PUSH GS
MOV CX,WORD PTR [BP+10] ;CX point to size (matrix of size*size)
MOV SI,WORD PTR [BP+6] ;SI point to pointer in *mat[] (points to rows)
MOV ES,WORD PTR [BP+8] ;Segment of *mat[]
MOV DI,WORD PTR ES:[SI] ;DI point to value in *mat[] (points to columns, with first pointer on rows so gives value)
MOV ES,WORD PTR ES:[SI+2] ;Segment of *mat[]
MOV I,0 ;Rows index counter
MOV J,0 ;Columns index counter
MOV Counter,CX
ADD Counter,CX ;Counter for loop
FirstGetN: ;Get number to check with all other numbers
MOV AX,WORD PTR ES:[DI] ;AX has value which DI is pointing to
MOV N,AX
FirstSubNumbers:
ADD DI,2 ;Point to next column
MOV AX,WORD PTR ES:[DI] ;AX has value one column ahead from N
SUB AX,N
CMP AX,0
JG Continue1
NEG AX ;Convert sub result to positive
Continue1:
MOV Min,AX ;Save minimum difference in Min for loop with compare ahead
MOV SI,WORD PTR [BP+12] ;SI point to *num1 (in case first check had the minimum difference)
MOV GS,WORD PTR [BP+14] ;Segment of *num1
MOV AX,N
MOV GS:[SI],AX ;*num1 = N
MOV SI,WORD PTR [BP+16] ;SI point to *num2
MOV GS,WORD PTR [BP+18] ;Segment of *num2
MOV AX,WORD PTR ES:[DI] ;AX = second number
MOV GS:[SI],AX ;*num2 = second number
GetN:
MOV SI,WORD PTR [BP+6]
MOV ES,WORD PTR [BP+8]
ADD SI,I ;Add needed row
MOV DI,WORD PTR ES:[SI]
MOV ES,WORD PTR ES:[SI+2]
ADD DI,J ;Add needed column
MOV AX,WORD PTR ES:[DI]
MOV N,AX ;N contains number being checked with others
MOV AX,I ;In order to move from N location forward (numbers before were checked during the loop)
MOV TempI,AX
MOV AX,J
MOV TempJ,AX
MOV AX,Counter
CMP TempJ,AX ;Meaning it's in last column
JE Fix
AddJ:
ADD TempJ,2 ;Move to next column
JMP SubNumbers
Fix:
MOV TempJ,0 ;Back to first column
ADD TempI,4 ;New row
SubNumbers:
MOV SI,WORD PTR [BP+6]
MOV ES,WORD PTR [BP+8]
ADD SI,TempI
MOV DI,WORD PTR ES:[SI]
MOV ES,WORD PTR ES:[SI+2]
ADD DI,TempJ
MOV AX,WORD PTR ES:[DI] ;AX contains number to check with N
MOV BX,N ;Move N to BX in order to save N's value
SUB BX,AX ;BX (N) -= AX
CMP BX,0
JG Continue2
Neg BX
Continue2:
MOV AX,Min
SUB AX,BX ;Substract former minimum and current sub result
CMP AX,0 ;To check which one is bigger
JLE Continue3 ;If BX > AX
MOV Min,BX ;Else, Min=BX
MOV SI,WORD PTR [BP+12] ;SI point to *num1
MOV GS,WORD PTR [BP+14] ;Segment of *num1
MOV AX,N
MOV GS:[SI],AX ;*num1 = N
MOV SI,WORD PTR [BP+16] ;SI point to *num2
MOV GS,WORD PTR [BP+18] ;Segment of *num2
MOV AX,WORD PTR ES:[DI] ;AX = second number
MOV GS:[SI],AX ;*num2 = second number
Continue3:
MOV AX,Counter
CMP TempJ,AX ;Meaning all columns were checked
JNE AddJ
MOV TempJ,0 ;Else, go to first column
ADD TempI,4 ;Next row
MUL Two
CMP TempI,AX ;Meaning all rows (and columns) were checked
JNE SubNumbers
MOV AX,Counter
ADD J,2 ;Move to next column with N number (J is pointing to INT so advance 2 bytes)
CMP J,AX
JNE GetN
Fix2:
MOV J,0
MOV AX,Counter
MUL Two
ADD I,4
CMP I,AX ;If all rows have been checked with N number (I is pointing to pointer so jumps of 4 byte, LARGE MODEL)
JE Finish
JMP GetN
Finish:
MOV AX,Min ;Save value to return
POP GS ;POP by LIFO order
POP ES
POP CX
POP DI
POP SI
POP BP
RET ;AX, IP and CS
_getDiffMin ENDP
END Start
谢谢。
答案 0 :(得分：0)
答案是我需要为“循环”添加2，因为“大小”（从C代码中获取）从0开始计数。
这是ASM代码：
;extern int getDiffMin(int *mat[], int size , int *num1 , int *num2)
; BP+6+8 BP+10 BP+12+14 BP+16+18
;
.MODEL LARGE ;Pointers size = 4 bytes
.DATA
I DW ?
J DW ?
N DW ?
Min DW ?
TempI DW ?
TempJ DW ?
Counter DW ?
Two DW 2
.CODE
.386
PUBLIC _getDiffMin
_getDiffMin PROC FAR
Start:
PUSH BP ;Save BP's current value
MOV BP,SP
PUSH SI
PUSH DI
PUSH CX
PUSH ES
PUSH GS
MOV CX,WORD PTR [BP+10] ;CX point to size (matrix of size*size)
MOV SI,WORD PTR [BP+6] ;SI point to pointer in *mat[] (points to rows)
MOV ES,WORD PTR [BP+8] ;Segment of *mat[]
MOV DI,WORD PTR ES:[SI] ;DI point to value in *mat[] (points to columns, with first pointer on rows so gives value)
MOV ES,WORD PTR ES:[SI+2] ;Segment of *mat[]
MOV I,0 ;Rows index counter
MOV J,0 ;Columns index counter
MOV Counter,CX
ADD Counter,2 ;Since size starts from 0, need to make our "loop" bigger by 2
FirstGetN: ;Get number to check with all other numbers
MOV AX,WORD PTR ES:[DI] ;AX has value which DI is pointing to
MOV N,AX
FirstSubNumbers:
ADD DI,2 ;Point to next column
MOV AX,WORD PTR ES:[DI] ;AX has value one column ahead from N
SUB AX,N
CMP AX,0
JG Continue1
NEG AX ;Convert sub result to positive
Continue1:
MOV Min,AX ;Save minimum difference in Min for loop with compare ahead
MOV SI,WORD PTR [BP+12] ;SI point to *num1 (in case first check had the minimum difference)
MOV GS,WORD PTR [BP+14] ;Segment of *num1
MOV AX,N
MOV GS:[SI],AX ;*num1 = N
MOV SI,WORD PTR [BP+16] ;SI point to *num2
MOV GS,WORD PTR [BP+18] ;Segment of *num2
MOV AX,WORD PTR ES:[DI] ;AX = second number
MOV GS:[SI],AX ;*num2 = second number
GetN:
MOV SI,WORD PTR [BP+6]
MOV ES,WORD PTR [BP+8]
ADD SI,I ;Add needed row
MOV DI,WORD PTR ES:[SI]
MOV ES,WORD PTR ES:[SI+2]
ADD DI,J ;Add needed column
MOV AX,WORD PTR ES:[DI]
MOV N,AX ;N contains number being checked with others
MOV AX,I ;In order to move from N location forward (numbers before were checked during the loop)
MOV TempI,AX
MOV AX,J
MOV TempJ,AX
MOV AX,Counter
CMP TempJ,AX ;Meaning it's in last column
JE Fix
AddJ:
ADD TempJ,2 ;Move to next column
JMP SubNumbers
Fix:
MOV TempJ,0 ;Back to first column
ADD TempI,4 ;New row
SubNumbers:
MOV SI,WORD PTR [BP+6]
MOV ES,WORD PTR [BP+8]
ADD SI,TempI
MOV DI,WORD PTR ES:[SI]
MOV ES,WORD PTR ES:[SI+2]
ADD DI,TempJ
MOV AX,WORD PTR ES:[DI] ;AX contains number to check with N
MOV BX,N ;Move N to BX in order to save N's value
SUB BX,AX ;BX (N) -= AX
CMP BX,0
JG Continue2
Neg BX
Continue2:
MOV AX,Min
SUB AX,BX ;Substract former minimum and current sub result
CMP AX,0 ;To check which one is bigger
JLE Continue3 ;If BX > AX
MOV Min,BX ;Else, Min=BX
MOV SI,WORD PTR [BP+12] ;SI point to *num1
MOV GS,WORD PTR [BP+14] ;Segment of *num1
MOV AX,N
MOV GS:[SI],AX ;*num1 = N
MOV SI,WORD PTR [BP+16] ;SI point to *num2
MOV GS,WORD PTR [BP+18] ;Segment of *num2
MOV AX,WORD PTR ES:[DI] ;AX = second number
MOV GS:[SI],AX ;*num2 = second number
Continue3:
MOV AX,Counter
CMP TempJ,AX ;Meaning all columns were checked
JNE AddJ
MOV TempJ,0 ;Else, go to first column
ADD TempI,4 ;Next row
MOV AX,Counter
ADD AX,2
MUL Two
CMP TempI,AX ;Meaning all rows (and columns) were checked
JNE SubNumbers
MOV AX,Counter
ADD J,2 ;Move to next column with N number (J is pointing to INT so advance 2 bytes)
CMP J,AX
JNE GetN
Fix2:
MOV J,0
ADD I,4
MOV AX,Counter
ADD AX,2
MUL Two
CMP I,AX ;If all rows have been checked with N number (I is pointing to pointer so jumps of 4 byte, LARGE MODEL)
JE Finish
JMP GetN
Finish:
MOV AX,Min ;Save value to return
POP GS ;POP by LIFO order
POP ES
POP CX
POP DI
POP SI
POP BP
RET ;AX, IP and CS
_getDiffMin ENDP
END Start